Gibbons Sean M, Lekberg Ylva, Mummey Daniel L, Sangwan Naseer, Ramsey Philip W, Gilbert Jack A
Graduate Program in Biophysical Sciences, University of Chicago, Chicago, Illinois, USA; Bioscience Division, The Microbiome Center, Argonne National Laboratory, Argonne, Illinois, USA; MPG Ranch, Missoula, Montana, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
MPG Ranch, Missoula, Montana, USA; Department of Ecosystem and Conservation Science, University of Montana, Missoula, Montana, USA.
mSystems. 2017 Mar 7;2(2). doi: 10.1128/mSystems.00178-16. eCollection 2017 Mar-Apr.
Plant invasions often reduce native plant diversity and increase net primary productivity. Invaded soils appear to differ from surrounding soils in ways that impede restoration of diverse native plant communities. We hypothesize that invader-mediated shifts in edaphic properties reproducibly alter soil microbial community structure and function. Here, we take a holistic approach, characterizing plant, prokaryotic, and fungal communities and soil physicochemical properties in field sites, invasion gradients, and experimental plots for three invasive plant species that cooccur in the Rocky Mountain West. Each invader had a unique impact on soil physicochemical properties. We found that invasions drove shifts in the abundances of specific microbial taxa, while overall belowground community structure and functional potential were fairly constant. Forb invaders were generally enriched in copiotrophic bacteria with higher 16S rRNA gene copy numbers and showed greater microbial carbohydrate and nitrogen metabolic potential. Older invasions had stronger effects on abiotic soil properties, indicative of multiyear successions. Overall, we show that plant invasions are idiosyncratic in their impact on soils and are directly responsible for driving reproducible shifts in the soil environment over multiyear time scales. In this study, we show how invasive plant species drive rapid shifts in the soil environment from surrounding native communities. Each of the three plant invaders had different but consistent effects on soils. Thus, there does not appear to be a one-size-fits-all strategy for how plant invaders alter grassland soil environments. This work represents a crucial step toward understanding how invaders might be able to prevent or impair native reestablishment by changing soil biotic and abiotic properties.
植物入侵往往会降低本地植物的多样性并提高净初级生产力。被入侵的土壤似乎在某些方面与周围土壤不同，这些方面阻碍了多样化本地植物群落的恢复。我们假设入侵植物介导的土壤性质变化会可重复地改变土壤微生物群落结构和功能。在这里，我们采用整体方法，对落基山脉西部共生的三种入侵植物物种在野外场地、入侵梯度和实验地块中的植物、原核生物和真菌群落以及土壤理化性质进行表征。每种入侵植物对土壤理化性质都有独特的影响。我们发现入侵导致特定微生物类群的丰度发生变化，而地下群落的整体结构和功能潜力相当稳定。阔叶入侵植物通常富含具有较高16S rRNA基因拷贝数的富营养细菌，并且显示出更大的微生物碳水化合物和氮代谢潜力。入侵时间较长的对非生物土壤性质的影响更强，这表明存在多年的演替过程。总体而言，我们表明植物入侵对土壤的影响具有特异性，并且在多年时间尺度上直接导致土壤环境发生可重复的变化。在本研究中，我们展示了入侵植物物种如何使土壤环境从周围的本地群落迅速转变。三种入侵植物中的每一种对土壤都有不同但一致的影响。因此，对于植物入侵者如何改变草原土壤环境，似乎不存在一刀切的策略。这项工作是理解入侵者如何通过改变土壤生物和非生物性质来阻止或损害本地植物重新建立的关键一步。
